An Automatically Switched Optical Network (ASON) is a dynamic automatically switched transport network and a new generation network, in which a user initiates a service request dynamically, a network element computes and selects a path automatically, and establishment, recovery and removal of a connection are integrated through signaling control. An ASON system structure is divided into three planes, including a transport plane, a control plane and a management plane.
An end-to-end service may be established automatically by a soft permanent connection and a switched connection through an ASON controller, thus greatly reducing the establishment complexity of an optical connection. However, the soft permanent connection is a service connection established by sending a command to a network element by the management plane through a network management controller. Each network element still needs to operate a service established by the network management controller on a plurality of boards and ports, thus a problem of automatic establishment is not solved.
For a transmission resource of a network element, besides a traditional management plane, the control plane is added to an ASON after the instruction of an ASON controller. That is, both a network management controller and the ASON controller are able to operate transmission resources of various boards and ports in the network element, thus leading to a problem of data consistency and resource conflicts are easily caused, and there are generally two solutions therefor.
The first method is to notify control conditions for resources to each other. In this way, resource conflicts can be avoided when two planes establish a service in different periods. However, there are still resource conflicts when services are established simultaneously. For example, when the ASON controller needs to use three resources A, B and C to establish a service 1 on a certain network element, the ASON controller has already sent to a board two resources A and B which need to be used, but has not sent the resource C to the board. Since the ASON controller has not sent to the board all resources which need to be used by the service 1, the network management controller is not notified at the moment. In the meanwhile, the network management controller, which needs to use resources E, B and D to start establishment of a service 2, will modified the resource B to be used by the network management controller without knowing that the resource B has already been used by the ASON controller. Then, although the service established by the ASON controller executes a command successfully, there is no signal actually.
The second method is resource division. That is, transmission resources in the network element are divided in advance so as to avoid mutual interference of transmission resources used by the management plane and the control plane. Although this method solves the problem of resource conflicts, a problem of resource waste is inevitable and there may be a shortage of resources on the management plane while there are idle resources on the control plane, or vice versa, which actually violates an original intention to make the ASON more flexible and more intelligent with the control plane.